Influent:Reject water
Anammox system:nan
Anammox reactor:Up Flow - Anaerobic Sludge Blanket Reactor (UASB) reactor
Medium:Granular sludge
Culture taken from:Anammox bacteria taken from facility treating wastewater of the Salutaguse Yeast Factory
Microorganism cultured:Sulfur cycle microorganisms
Respiration:Anaerobic
Electron donor:Ammonium sulfate ((NH4)2SO4), Reject water
Electron acceptor:Potassium sulfate (K2SO4), Sodium nitrite (NaNO2)
PH:7.8–8.1
Maximum sludge concentration:1.87
HRT:1–2 d
NH4–N Influent conc(mg/L):158
NO2–N Influent conc(mg/L):nan
SO4–S Influent conc(mg/L):123
NH4–N Removal efficiency (%):30
NO2–N Removal efficiency (%):nan
SO4-S Removal efficiency (%):nan
NLR kg-N/m3/d:0.22
NRR kg-N/m3/d:4.8
Major findings:Study into SRAO showed that sulphate can be used as an alternative electron acceptor in nitrogen removal
Authors:Rikmann et al., 2014
Title:Comparison of sulfate-reducing and conventional Anammox upflow anaerobic sludge blanket reactors
Pubmed link:Link
Full research link:Link
Abstract:Autotrophic NH4(+) removal has been extensively researched, but few studies have investigated alternative electron acceptors (for example, SO4(2-)) in NH4(+) oxidation. In this study, sulfate-reducing anaerobic ammonium oxidation (SRAO) and conventional Anammox were started up in upflow anaerobic sludge blanket reactors (UASBRs) at 36 (±0.5)°C and 20 (±0.5)°C respectively, using reject water as a source of NH4(+). SO4(2-) or NO2(-), respectively, were applied as electron acceptors. It was assumed that higher temperature could promote the SRAO, partly compensating its thermodynamic disadvantage comparing with the conventional Anammox to achieve comparable total nitrogen (TN) removal rate. Average volumetric NH4(+)-N removal rate in the sulfate-reducing UASBR1 was however 5-6 times less (0.03 kg-N/(m(3) day)) than in the UASBR2 performing conventional nitrite-dependent autotrophic nitrogen removal (0.17 kg-N/(m(3) day)). However, the stoichiometric ratio of NH4(+) removal in UASBR1 was significantly higher than could be expected from the extent of SO4(2-) reduction, possibly due to interactions between the N- and S-compounds and organic matter of the reject water. Injections of N2H4 and NH2OH accelerated the SRAO. Similar effect was observed in batch tests with anthraquinone-2,6-disulfonate (AQDS). For detection of key microorganisms PCR-DGGE was used. From both UASBRs, uncultured bacterium clone ATB-KS-1929 belonging to the order Verrucomicrobiales, Anammox bacteria (uncultured Planctomycete clone Pla_PO55-9) and aerobic ammonium-oxidizing bacteria (uncultured sludge bacterium clone ASB08 "Nitrosomonas") were detected. Nevertheless the SRAO process was shown to be less effective for the treatment of reject water, compared to the conventional Anammox.